Electro-magnet



(No Model.)

C. E. LIPE.

ELECTRO MAGNET.

No. 452,003. Patented May 12,1891.

S14/vanto@ WW1/bww@ y I J W 5/ awo w: nonms wetens no., mom-uws.,wAsHmm'oN, n. c.

UNITED STATES PATENT OEEICE.

CHARLES E. LIFE, OF SYRAOUSE, NEV YORK.

LECTRO-MAGNET.

SPECIFICATION forming part of Letters Patent No. 452,003, dated May 12,1891. Application tiled November 20, 1889. Serial No. 331,008. (Nomodel.)

T0 all whom it may concern.-

Beit known that I, CHARLES E. LIPE, a citizen of the United States,residing at Syracuse, in the county of Onondaga and State of New York,have invented certain new and useful Improvements in Electro-MagneticOoils; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

My invention relates to certain new and useful improvements inelectro-magnetic coils, and particularly electro-magnetic coils of thekind employed to actuate reciprocating tools for mining` and otherpurposes, and wherein the convolutions are traversed by powerfulcurrents from dynamo-electric machines. In electro-magnetic coils of thekind referred to the character of the current employed requires Wire ofcorrespondingly-great carrying capacity, and Wire Whose insulation willnot be liable to be charred or destroyed by the heating effects ofcurrents of extra intensity. It is also desirable to reduce thedimensions of the coils to the smallest lim-its practicable, so that thereciprocating tool as a whole may be less cumbersome and more readilymanipulated by the operator. In order, however, that this reduction insize may be accomplished without loss in mechanical energy, it isessential not to diminish the number of layers of convolutions normallyrequired to develop the desired magnetic strength for a given current,but if possible, while retaining the necessary cross-sectional area ofthe wire and preserving its complete insulation, to concentrate within asmaller space a greater number of concentric layers of oonvolutions anda greater number of convolutions in each layer, so that the strength ofthe coil as a whole may be increased rather than diminished.

The object of my invention is to produce an electro-magn etic coilhaving the particular characteristics described, thereby combining theminimum external dimensions with the maximum magnetic efficiency andwith permanent reliable insulation, a construction -peculiarly adaptedto the principal uses for which I contemplate employing it.

In the accompanying drawings, wherein I have illustrated the preferredform of my invention, Figure l represents in longitudinal section anelectro-magnetic coil embodying said invention, the section being takenon a plane indicated by the linel 1 of Fig. 2. Fig. 2 represents atransverse section and partial elevation taken on a plane indicated bythe line 2 2 of Fig. l. Fig. 3 represents approximately the preferredcross-section of the wire before coilin g and its cross-sectionthereafter.

Similar letters of reference indicate similar parts throughout theseveral views.

In carrying out my invention I make use of wire substantiallyrectangular in cross-section, although preferably deviating somewhattherefrom, as indicated at a in the left-hand view of Fig. 3, whereinthe cross-section is shown as a quadrilateral ligure having twoslightly-acute angles at the top and two slightly-obtuse angles at thebase. I find the use of wire of this particular cross-section ofadvantage, for the reason that in the act of coiling such wire to formthe magnet-convolutions it assumes the rectangular crosssectionindicated at b in the right view of Fig. S-that is, the wire, originallyof the slightly irregular cross section described, becomes in coiling ofregular cross-section, and for the reason that the ceiling operationstretches the outer part of the wire represented by tlie top side of theirregular quadrilateral figure and compresses the inner part, or thatnearest the mandrel upon which the wire is wound. The effect of thestretching of the outer part of the coiled wire is to lessen the widthof said outer part, while the compression of the inner part increasesthe width of the latter. The wire when coiled, therefore, is ofsubstantially equal width throughout, so that the intervening space forthe insulation between the convolutions shall be substantially equal inwidth at top and bottom. The insulation can therefore be made by theinterposition of insulating material of regular thickness-sucl1 asstrips or spiral disks of mica-which will occupy the entire interveningspace between the convolutions, enabling the convolutions and separatinginsulation to be oompactly arranged, thereby obtaining a greater numberof convolutions within a given space. Anotable YOU economy inconsumption of mica is 4also effeeted as the result of this particulai`arrangement, as no more mica is required between` the convolutions thanthat necessary for their effective insulation.

My preferred manner of coiling the wire to make the coil is to wind itupon a suitable mandrel-such as a cylindrical iron rod-in a regularspiral, and during the winding operation interposing between the edgesof the convolutions strips of mica. On the completion of the firstspiral or layer of convolutions I cover or inwrap the exterior` surfaceof said spiral with a sheet or sheets of mica, and upon this mica bed Iwind the second layer of convolutions, and preferably in such manner asto break joints with the first layert'. e., so that the convolutions ofthe second layer will be wound over the dividing-line between theconvolutions of the first layer. The second spiral is then covered orinwrapped with mica in the same manner as the second spiral, and thethird spiral is thereupon wound over thedividing-line, separating theconvolutions of the first spiral in the manner described, care beingtaken during the winding of all the spirals to interpose be.

tween the convolutions thereof the insulating` strips or spiral disks ofmica above referred to. Subsequent spirals or layers of convolutionswith their separating insulation of mica are made in like manner untilthe coil has attained its desired dimensions.

In practice I have found it convenient to employ sixty convolutions foreach of the spiral layers and from eighteen to twenty of the spirallayers themselves, the length and diameter of the coil beingapproximately equal. These particular dimensions and number ofconvolutions and layers of convolutions are however not of the essenceof my invention, but are merely given as an exemplification of oneembodiment thereof.

In Figs. l and 2 of the drawingsI have shown the coil constructed asabove described and provided with a suitable insulating-Casin g and itsadjuncts, wherebyit is adapted for use in a reeiprocatin g electricalengine or drill. The leading-in wire h is connected to a terminal platec, and the outgoing end of said wire is connected to a terminal plateCZ, whereby the coil may be readily put in circuit with the line. Thecoil is preferably surrounded bya easing A of sheet brass separated fromthe exterior of the coil by a heavy layer e of mica and from the ends ofthe coils by disks f, also of mica. After the mandrel upon which thecoil has been wound is withdrawn the coil has the hollow interior B forthe reception of the reciprocating tool or drill of the electricalengine, which drill may conveniently work within the insulating-bcariugsy] at opposite ends of the casing.

It is evident that I may in some instances employ instead of micaequivalent substances having similar capacity for resisting heat andsimilar insulating properties, although in most cases I prefer theemployment of mica. It is also evident that instead of winding the coilin a series of superposed longitudinal spirals it may be wound in theform of a succession of flat spirals separated from each other byintervening circular disks of mica, and the convolutions of each spiralbeing separated by the interposition of mica between them, the maincharacteristics of my invention being, broadly, an electro-magnetic coilwhose individual convolutions and layers of convolutions are made up ofnaked rectangular wires separated from each other by mica or itsequivalent hard, insulating, fireresisting substance.

My improved coil is practically solid throughout, being made up ofrectangular wire with the interposition of a hard nonelastic insulatingmaterial, which will not yield or be compressed by the violent shocksand vibrations to which the coil is subjected when used in the electricdrills or miningmachines for which it is intended. The said shocks andvibrations will not, therefore, have the effect of loosening the coilconvolutions or of cutting through the insulating material, objectionswhich are inherent in the usual form of coils employed for suchmachines.

Having thus described my invention, what I claim is 1. A practicallysolid coil of substantially rectangular naked wire having its individualconvolutions and its layers `of convolutions separated by layers ofhard, insulating, fireresisting material. Y

2. A practically solid coil of substantially rectangular wire consistingof alternate layers of mica sheets and substantially rectanguiar wirewound one 'upon the other, and mica strips separating the individualconvolutions.

' he method of producing an electro-mag- IOO IIO

